521 research outputs found
High Temperature Strain Gage Calibration Fixture
An apparatus and method are described for calibrating high temperature strain gases which serve for both dead weight and constant deflection measurements. A cantilever support arm allows the test unit to slide into a furnace while one end is subjected to bending strain either by hanging weights upon it or by deflecting it with a push rod. The dual nature of the fixture permits both tests to be run without change of the test specimen or removal from the furnace
Hot foil transducer skin friction sensor
The device utilizes foil transducers with only one edge exposed to the fluid flow. The surfaces are polished producing a foil transducer that does not generate turbulence while sufficiently thick to carry the required electrical current for high temperature fluid flow. The assembly utilizes a precut layered metal sandwich with attached electrodes eliminating a need for welding and individual sensor calibration
How well do domain wall fermions realize chiral symmetry?
In the domain wall fermion formulation, chiral symmetry breaking in full QCD
is expected to fall exponentially with the length of the extra dimension. We
measure the chiral symmetry breaking due to a finite extra dimension in two
ways, which can be affected differently by finite volume and explicit fermion
mass. For quenched QCD the two methods generally agree, except for the largest
extent of the extra dimension, which makes the limit uncertain. We have less
data for full QCD, but see exponential suppression for the method where we have
data.Comment: 3 pages, 2 figures, LATTICE99(hightemp
Impact energy absorber Patent
Impact energy absorber with decreasing absorption rat
Dynamical QCD thermodynamics with domain wall fermions
We present results from numerical simulations of full, two flavor QCD
thermodynamics at N_t=4 with domain wall fermions. For the first time a
numerical simulation of the full QCD phase transition displays a low
temperature phase with spontaneous chiral symmetry breaking but intact flavor
symmetry and a high temperature phase with the full SU(2) x SU(2) chiral flavor
symmetry.Comment: LATTICE98(hightemp
Domain wall fermions and applications
Domain wall fermions provide a complimentary alternative to traditional
lattice fermion approaches. By introducing an extra dimension, the amount of
chiral symmetry present in the lattice theory can be controlled in a linear
way. This results in improved chiral properties as well as robust topological
zero modes. A brief introduction on the subject and a discussion of chiral
properties and applications, such as zero and finite temperature QCD, N = 1
super Yang-Mills, and four-fermion theories, is presented.Comment: Contribution to Lattice 2000 (Plenary), LaTeX, 12 pages, 15 eps
figure
The finite temperature QCD phase transition with domain wall fermions
Results from the Columbia lattice group study of the QCD finite temperature
phase transition with dynamical domain wall fermions on
lattices are presented. These results include an investigation of the U(1)
axial symmetry breaking above but close to the transition, the use of zero
temperature calculations that set the scale at the transition and preliminary
measurements close to the transition.Comment: LATTICE99(hightemp), LaTeX, 3 pages, 3 eps figure
Dynamical lattice QCD thermodynamics with domain wall fermions
We present results from simulations of two flavor QCD thermodynamics at N_t=4
with domain wall fermions. In contrast to other lattice fermion formulations,
domain wall fermions preserve the full chiral symmetry of the continuum at
finite lattice spacing (up to terms exponentially small in an extra parameter).
Just above the phase transition, we find that the axial U(1) symmetry is broken
only by a small amount. We discuss an ongoing calculation to determine the
order and properties of the phase transition using domain wall fermions, since
the global symmetries of the theory are expected to be important here.Comment: 4 pages, 4 eps figures, LaTeX. To appear in the Proceedings of the
XVth Particles and Nuclei International Conference (PANIC '99), Uppsala,
Sweden, 10-16 June 199
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